UI bug when using action plugins or switching canvas

[Andrzej Szombierski]

Tested with the latest GIT version as of today (101b68b610d4334db68f1e4ba9e287b37f65c9a6), under Ubuntu 16.04.4 LTS, kicad installed from nightly PPA behaves the same as built from source.

1. Launch pcbnew (from a project or standalone, does not matter)
2. Execute any action plugin script (may be empty). OR switch the canvas to legacy and back
3. See an assertion on the console:
Gdk-CRITICAL **: IA__gdk_window_thaw_updates: assertion 'impl_window->update_freeze_count > 0' failed

4. Observe that the current layer combobox gets cleared, and the Layers/Items panel does weird things when switching (see screenshot). Other aspects of the UI also have problems.

I've traced the problem down to the following area:

After executing a plugin, PCB_EDIT_FRAME::UpdateUserInterface() is called. This in turn calls:
m_Layers->Freeze() ... m_layers->SelectLayer (from syncLayerWidgetLayer) ... m_layers->Thaw()

Inside LAYER_WIDGET::SelectLayer (->SelectLayerRow), commenting out the following lines makes the assertion go away:
m_notebook->SetSelection( 0 );
getLayerComp( aRow, 1 )->SetFocus();

I don't understand how this can interfere with freezing/thawing.

[Andrzej Szombierski (qq-q)]

Full version info dump:

Application: pcbnew
Version: 5.0.0-rc3-unknown-101b68b~65~ubuntu16.04.1, release build
Libraries:
    wxWidgets 3.0.2
    libcurl/7.47.0 OpenSSL/1.0.2g zlib/1.2.8 libidn/1.32 librtmp/2.3
Platform: Linux 4.4.0-130-generic x86_64, 64 bit, Little endian, wxGTK
Build Info:
    wxWidgets: 3.0.2 (wchar_t,wx containers,compatible with 2.8) GTK+ 2.24
    Boost: 1.58.0
    OpenCASCADE Community Edition: 6.8.0
    Curl: 7.47.0
    Compiler: GCC 5.4.0 with C++ ABI 1009

Build settings:
    USE_WX_GRAPHICS_CONTEXT=OFF
    USE_WX_OVERLAY=OFF
    KICAD_SCRIPTING=ON
    KICAD_SCRIPTING_MODULES=ON
    KICAD_SCRIPTING_WXPYTHON=OFF
    KICAD_SCRIPTING_ACTION_MENU=ON
    BUILD_GITHUB_PLUGIN=ON
    KICAD_USE_OCE=ON
    KICAD_USE_OCC=OFF
    KICAD_SPICE=ON

[Andrzej Szombierski (qq-q)]

This turned out to be a bug in wxWidgets (wxGtk). Dropping this information here for anyone else stumbling upon this problem.

Bug tracker: http://trac.wxwidgets.org/ticket/16795
Fix commit: https://github.com/wxWidgets/wxWidgets/commit/b7cf54d24afb76c87b106435c01fee774284e1a6

I've managed to solve this issue by rebuilting wxGtk with the above commit backported.

[Jeff Young (jeyjey)]

The fix appears to be in wxWidgets 3.1.0, which we will hopefully be moving to at some not-too-distant future.